RESUMEN
<p><b>OBJECTIVE</b>To investigate the mutation in transcription factor paired box gene PAX9 in a mongolian family with non-syndromic oligodontia.</p><p><b>METHODS</b>Peripheral blood was collected from 17 core family members (9 unaffected, 8 affected) in this Mongolian family with non-syndromic oligodontia. Mutation in exons of PAX9 gene was identified by PCR amplification and DNA sequencing.</p><p><b>RESULTS</b>A point mutation c.87G > C at position 87 in exon 4 of PAX9 was identified from 8 affected members in the family, which were G/C heterozygous.While the 9 healthy members in the family were homozygous for C which was consistent with normal reference sequence in the GenBank(accession number: NC_000014).</p><p><b>CONCLUSIONS</b>The mutation of c.87G > C (p. Ala240Pro) in exon 4 of PAX9 was likely to cause the non-syndromic oligodontia in this Mongolian family.</p>